Several applications are known in which connections need to be provided under water, such as electrical connections and/or optical connections. Examples include a subsea installation for the production of hydrocarbons from a subsea well, in which different components of the subsea installation may need to be connected for power transfer and/or data communication. Such connections may for example comprise a connection from a topside installation, such as a floating or fixed platform or from an on-shore site to a subsea component, for example by means of an umbilical or a subsea cable. Other connections include electrical connections between different type of subsea equipment, such as a connection between a subsea transformer and subsea switchgear for the transfer of electrical power.
Subsea production equipment, such as pumps or compressors, may have a significant power consumption and may accordingly require the use of high voltage electric power connections. For a three-phase electrical connection, three high voltage subsea wet-mateable connectors may be required and may need to be mated subsea. In a typical application, the subsea connector halves are mounted to respective stabplates, and three or more electrical connections may be established by bringing the two stab plates into engagement. Since in such arrangements, the mating forces of three or more subsea wet-mateable connectors need to be overcome simultaneously, a total mating force of the two stabplates of significant magnitude needs to be applied during mating. It is generally difficult to apply these high mating forces by means of a remotely operated vehicle (ROV).
To reduce the mating force of the respective connectors, the documents EP 2 854 234 A1 and EP 2 854 235 A1 disclose latching mechanisms between a shuttle pin of a female connector part and a pin of a male connector part by means of which the mating force between the two connector parts can be reduced. By making use of these configurations, it becomes possible to simultaneously mate plural high voltage wet-mateable connectors in stabplate assemblies by means of an ROV. The two stabplates usually comprise a locking mechanism that locks the stabplates together and thus holds the connector halves in the mated state. Consequently, the subsea wet-mateable connectors generally do not comprise any locking mechanism themselves, since they are locked together by the stab plate assembly.
When installing components of a subsea installation, there are often only specific time slots when the weather conditions are such that the subsea equipment can be installed by means of a floating vessel. It is often the case that one component is installed, whereafter the weather conditions change so that the vessel has to return to shore. A significant amount of time can pass before the next component is installed. The same problems occur when components are being exchanged or serviced. In this respect, it is problematic that high voltage subsea wet-mateable connectors can only be exposed to the seawater environment in an unmated state for a certain period of time, for example 30 or 60 days, that accumulates over the lifetime of the connector. For the above outlined reasons, it regularly occurs that unmated connectors are deployed subsea and that a significant amount of time passes before the connector parts are connected to complementary connector parts of another component of the subsea installation. For protecting the subsea deployed connectors from the subsea environment, so called dummy plugs may be used, which are essentially complete wet-mateable connectors without any cable connection that serve the main purpose of protecting the complementary connector half.
As described above, in applications where the connectors are mated by means of a stabplate mating mechanism, the connectors do themselves not comprise any locking features for locking the two connector halves together, so that the use of stand-alone dummy plugs is not possible. Providing a complementary stabplate with plural dummy plugs allows the protection of the subsea deployed wet-mateable connectors, yet the cost of providing such configuration for the purpose of protection are prohibitive.
From conventional wet-mateable connectors where single connector halves are mated by means of an ROV, it is known to use an external latching mechanism that latches the two connector halves together. The use of such external latching mechanism in the above outlined stab plate configurations is generally not desirable, since these mechanisms are prone to marine growth, and they may cause the connector halves to be become locked in the mated state. Furthermore, this would require a modification of the high voltage wet-mate connectors which increases costs and adds complexity to the connectors which may lead to an additional failure mechanism.
It is thus desirable to provide cost efficient protection of subsea wet-mateable connectors, in particular connectors that are mated by use of a stabplate mating mechanism. Furthermore, it is desirable to not further increase the complexity of the subsea wet-mate connectors. Also, it is desirable to improve the mating and de-mating of the wet-mateable connectors in such stabplate mating mechanism. It is desirable to efficiently protect subsea deployed wet-mateable connector parts against the negative effects of seawater exposure in a cost efficient way.